1561173233 has 2 divisors, whose sum is σ = 1561173234. Its totient is φ = 1561173232.

The previous prime is 1561173167. The next prime is 1561173239. The reversal of 1561173233 is 3323711651.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1558117729 + 3055504 = 39473^2 + 1748^2 .

It is a cyclic number.

It is not a de Polignac number, because 1561173233 - 2¹⁰ = 1561172209 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1561173233.

It is not a weakly prime, because it can be changed into another prime (1561173239) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 780586616 + 780586617.

It is an arithmetic number, because the mean of its divisors is an integer number (780586617).

Almost surely, 2^1561173233 is an apocalyptic number.

It is an amenable number.

1561173233 is a deficient number, since it is larger than the sum of its proper divisors (1).

1561173233 is an equidigital number, since it uses as much as digits as its factorization.

1561173233 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 11340, while the sum is 32.

The square root of 1561173233 is about 39511.6847653957. The cubic root of 1561173233 is about 1160.0686723614.

Adding to 1561173233 its reverse (3323711651), we get a palindrome (4884884884).

The spelling of 1561173233 in words is "one billion, five hundred sixty-one million, one hundred seventy-three thousand, two hundred thirty-three".